Context. The INTEGRAL observatory operating in a hard X-ray/gamma domain has
gathered a large observational data set over nine years starting in 2003. Most
of the observing time was dedicated to the Galactic source population study,
making possible the deepest Galactic survey in hard X-rays ever compiled. Aims.
We aim to perform a Galactic survey that can be used as the basis of Galactic
source population studies, and perform mapping of the Milky Way in hard X-rays
over the maximum exposure available at |b|<17.5 deg. Methods. We used sky
reconstruction algorithms especially developed for the high quality imaging of
INTEGRAL/IBIS data. Results. We present sky images, sensitivity maps, and
catalogs of detected sources in the three energy bands 17-60, 17-35, and 35-80
keV in the Galactic plane at |b|<17.5 deg. The total number of sources in the
reference 17-60 keV band includes 402 objects exceeding a 4.7 sigma detection
threshold on the nine-year time-averaged map. Among the identified sources with
known and tentatively identified natures, 253 are Galactic objects (108
low-mass X-ray binaries, 82 high-mass X-ray binaries, 36 cataclysmic variables,
and 27 are of other types), and 115 are extragalactic objects, including 112
active galactic nuclei (AGNs) and 3 galaxy clusters. The sample of Galactic
sources with S/N>4.7 sigma has an identification completeness of ~92%, which is
valuable for population studies. Since the survey is based on the nine-year sky
maps, it is optimized for persistent sources and may be biased against finding
transients.Comment: 18 pages, 7 figures, long table, Astronomy and Astrophysics 545, A2
